CA1047083A - Auxiliary interlock switch with interchangeable and reversible chisel-shaped contacts and spring biasing mechanism - Google Patents
Auxiliary interlock switch with interchangeable and reversible chisel-shaped contacts and spring biasing mechanismInfo
- Publication number
- CA1047083A CA1047083A CA251,796A CA251796A CA1047083A CA 1047083 A CA1047083 A CA 1047083A CA 251796 A CA251796 A CA 251796A CA 1047083 A CA1047083 A CA 1047083A
- Authority
- CA
- Canada
- Prior art keywords
- contact
- posts
- interlock switch
- receiving
- bridging
- 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
Links
- 230000002441 reversible effect Effects 0.000 title abstract 2
- 229910052751 metal Inorganic materials 0.000 claims abstract description 5
- 239000002184 metal Substances 0.000 claims abstract description 5
- 230000006835 compression Effects 0.000 claims description 9
- 238000007906 compression Methods 0.000 claims description 9
- 230000005294 ferromagnetic effect Effects 0.000 description 3
- 239000000543 intermediate Substances 0.000 description 3
- 230000005291 magnetic effect Effects 0.000 description 3
- 239000000969 carrier Substances 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 238000007373 indentation Methods 0.000 description 2
- 239000011810 insulating material Substances 0.000 description 2
- 238000003754 machining Methods 0.000 description 2
- 230000003405 preventing effect Effects 0.000 description 2
- 229910001369 Brass Inorganic materials 0.000 description 1
- ZLSWBLPERHFHIS-UHFFFAOYSA-N Fenoprop Chemical compound OC(=O)C(C)OC1=CC(Cl)=C(Cl)C=C1Cl ZLSWBLPERHFHIS-UHFFFAOYSA-N 0.000 description 1
- 241000282320 Panthera leo Species 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- DMFGNRRURHSENX-UHFFFAOYSA-N beryllium copper Chemical compound [Be].[Cu] DMFGNRRURHSENX-UHFFFAOYSA-N 0.000 description 1
- 239000010951 brass Substances 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229940086255 perform Drugs 0.000 description 1
- 150000002989 phenols Chemical class 0.000 description 1
- 229920001225 polyester resin Polymers 0.000 description 1
- 239000004645 polyester resin Substances 0.000 description 1
- 239000012858 resilient material Substances 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 229920001187 thermosetting polymer Polymers 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H1/00—Contacts
- H01H1/12—Contacts characterised by the manner in which co-operating contacts engage
- H01H1/14—Contacts characterised by the manner in which co-operating contacts engage by abutting
- H01H1/20—Bridging contacts
- H01H1/2083—Bridging contact surfaces directed at an oblique angle with respect to the movement of the bridge
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H1/00—Contacts
- H01H1/12—Contacts characterised by the manner in which co-operating contacts engage
- H01H1/14—Contacts characterised by the manner in which co-operating contacts engage by abutting
- H01H1/20—Bridging contacts
- H01H1/2025—Bridging contacts comprising two-parallel bridges
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H1/00—Contacts
- H01H2001/001—Contacts providing easy replacement of contacts
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H50/00—Details of electromagnetic relays
- H01H50/54—Contact arrangements
- H01H50/541—Auxiliary contact devices
- H01H50/545—Self-contained, easily replaceable microswitches
Abstract
AUXILIARY INTERLOCK SWITCH WITH INTERCHANGEABLE
AND REVERSIBLE CHISEL-SHAPED CONTACTS AND
SPRING BIASING MECHANISM
ABSTRACT OF THE DISCLOSURE
An auxiliary interlock switch for a DC contactor has a reciprocable one-piece insulating contact carrier and plural bridging contacts interchangeably mounted thereon in alternative positions to provide different desired arrangements of normally open and normally closed contact sets with the stationary contact posts. The contact carrier has a return spring compressed within a spring-receiving cavity and elongated abutment-receiving apertures registering with opposite ends of said cavity through which an abutment member, that is releasably assembled to the contact carrier, may interchangeably freely extend to permit relative movement therebetween and against which one end of the return spring reacts to resiliently bias the contact carrier against reciprocation in one direction. The bridging contacts may be easily removed in the field and reassembled in desired contact configuration and are of resilient metal with bifurcated ends having "chisel" surfaces which provide high unit area contact pressure and plural points of engagement with each stationary contact post to thereby increase electrical reliability.
AND REVERSIBLE CHISEL-SHAPED CONTACTS AND
SPRING BIASING MECHANISM
ABSTRACT OF THE DISCLOSURE
An auxiliary interlock switch for a DC contactor has a reciprocable one-piece insulating contact carrier and plural bridging contacts interchangeably mounted thereon in alternative positions to provide different desired arrangements of normally open and normally closed contact sets with the stationary contact posts. The contact carrier has a return spring compressed within a spring-receiving cavity and elongated abutment-receiving apertures registering with opposite ends of said cavity through which an abutment member, that is releasably assembled to the contact carrier, may interchangeably freely extend to permit relative movement therebetween and against which one end of the return spring reacts to resiliently bias the contact carrier against reciprocation in one direction. The bridging contacts may be easily removed in the field and reassembled in desired contact configuration and are of resilient metal with bifurcated ends having "chisel" surfaces which provide high unit area contact pressure and plural points of engagement with each stationary contact post to thereby increase electrical reliability.
Description
This invention relates to electromagnetic circuit makers and breakers of the contactor t~pe and in particular to auxiliary interlock switches for DC contactors.
BACKGROUND OF THE INVENTION
Contactors are often provided with'an auxiliary interlock switch which has a plurality of sets of electrical contacts for controlling auxiliary circuits such as the operating coils of auxiliary devices. ' ;~
Known auxiliary interlock switches are constructed ~ ' 10 from a large numb`er of separate pieces which require special ' fixtures and jigs to hold the pieces together during assem-bly, make change of contact arrangement in the field vir- , tually impossible, and substantially increase both the ~, number of machining and handling operations as well as the cost of the unit.--'Further, the electrical reliability of -known auxiliary interlock switches is relatively low in that ;
contamination of-the contacts~often-prevent completion of a low voltage auxiliary circuit even though the contacts of the interlock are operated into engagement by the electro-20 magnetic contactor. ' OBJECTS OF THE INVENTION
It is an object of the invention to provide an-im-proved auxiliary interlock switch for a contactor which o'bviates the above disadvantages of prior art devices and has substantially fewer parts than known interlocks. It i5 a further object of the invention to provide such an improved auxiliary interlock switch which does not require special ~ , fixtures and jigs to assemble'the parts and wherein the movable contacts are easily assembled on the contact carriex and can be'facilely changed in the'fiel'd to provide any desired arrangement of contact sets. Another'object of the '- 1- ~ -, ~ 7~B3 invention is to provide such an lmproved auxiliary interlock switch which is less expensive than known devices and re~uires ~ewer machining and handl'ing operations to construct.
~ still further object of the invention is to pro-vide such an improved auxiliary interlock switch which can easily be converted so that its reciprocable contact carrier is alternativeIy resiliently biased by the return spring to either a central position or to extreme positions in either direction from the central position. Still another object 10' is to provide such an improved interlock switch for a contactor which, in comparison to prior art auxliary inter-locks, has higher unit contact pressure and substantially improved electrical reliability. ;~' SUMMARY OF THE INVENTION
An auxiliary interlock switch embodying the inven-tion has increased electrical reliability in comparison to known devices ana permits easy-change-of the auxiliary con- '~
tact arrangement in the field. A reciprocable, one-piece insulating contact carrier is provided with a cavity in which a helical return spring is captive and first and second abutment-receiving apertures which register with opposite ends of the spring-receiving cavity and in which an abutment member may interchangeably-ke positioned with its ends affixed to opposed sidewalls of the interloc]~
housing so that the return spring reacts against the abut-ment member and biases the carrier toward reciprocation in a desired direction. The contact carrier also has a plur-- alit~ of contact-receiving apertures in each of which a metallic bridging contact of generally U-shaped croSS section with diYerging ends is held captive by a loaded compression spring with'the'cross-piece of the'U-shaped contact abutting 1C)47~83 against one end o~ the contact-receiVing aperture. The ~ridging contacts may be easily removed in the field from the contact-receiving ape.rtures and reversed in direction to provide normall~ open or normally closed sets of auxiliary contacts with the stationary contact posts, or may alterna-tively be disposed against the opposite end of the contact-receiving aperture in order to provide different arrangements of normally open and normally closed auxiliary contact sets, as desired. The bridging contacts are of resilient material and the legs thereof are bïfurcated and have "chisel" shape surfaces which provide plural points of high unit area pressure arrangement with unitary stationary contact posts affixed to the interlock housing and substantially increase electrical reliability. -DESCRIPTION OF THE DRAWINGS
These and other objects and advantages of the in-vention will be more readily apparent from the following detailed description when considered in conjunction with the accompanying drawing wherein:
Fig. l.. is a fron.t view.. o~.a.. known contactor pro--~-vided with.the improved auxiliary interlock switch of the .
invention;
Figs. 2, 3 and 4 are left side, front and bottom views respectively of the housing of the auxiliary interlock switch embod.ying the invention shown in Fig. l;
Fig. 5 is a view of the open end of the right half of the interlock switch housing shown in Figs. 2-4 with the left housing half, contact carrier, and abutment member removed;
Fig. 6 is a View simil~r to Fig~ 5 but having the right housing half assembled with the contact carrier and a centering abutment member which biases the contact to a central position within the hbusing;
IL7~il3 Fig. 7 is a view similar to F~. 6 havin~ the con-tact carrier assembled with an end abutment member which biases the contact carrier to an extreme position in one direction;
Fig. 8 is a right side view of the reciprocable con-tact carrier removed from the housing and assembled with a ;
centering abutment member;
Fig. 9 is a sectional view taken along line IX-IX ~:
of Fig. 8;
10 ' Fig. 10 is a section view through the reciprocable contact carrier removed from the housing and assembled with an end abutment member;
Fig. 11 is a partial vertical, section view taken through the auxiliary interlock switch along line XI-XI of Fig. 6; and Fig. 12 is a perspective view of one of the bridging ';~
contacts.
DETAILED DESCRIPTION
Referring to Fig. 1 of the drawing, a known con- ', -tactor--10-may have-a U-shaped=ferromagnetic frame-~l-l which-~embraces a---cylindrical operating coil 12 wound in surrounding relation to a ferromagnetic core 14 extending axially of coil 12. A ferromagnetic armature 16 pivotally connected to one leg 17 of frame 11 is pulled against the other leg 18 of the frame to operate the contactor when coil 12 is ener- ,~
gized. The contactor movable main contact 19 is carried by armature 16 and may be electrically connected by a flexible lead ~ot shownl to a texminal block 2Q and .is adapted to engage a main stationary contact 22 when; armature 16 is attracted to core'l4. Stationary contact 22 is electrically connected to one'end of a metallic bus bar 23'which at its , ~Ofl~7~3 opposi-te end is connected to a helical elec-trical blowout coil 24. The arc, which is formed when contacts l9 and 22 separate, transfers to and is interrupted in an arc chute 26 having pole pieces 27 ~only one of which is shown~ between which the magnetic field generated by blowout coil 24 ex-tends. Only one of the flux carrying members 28 is shown which transfer the magnetic flux from blowout coil 24 to pole pieces 27.
The auxlliary interlock switch 29 for controlling auxiliary circuits includes an insulating housing 30 mounted on 10 a support bracket 31 and is actuated by reciprocation of an elongated operating member, or contact carrier 32 slidably mounted within housing 30. The ends of a U-shaped interlock actua*ing member 33 are secured to armature 16, and the cross-piece 34 of member 33 actuates contact carrier 32 longitudinally to operate the interlock switch 29 when armature 16 is attracted to frame ll. Cross-piece 34 may fit within an elongated groove 35 provided in a member 36 attached to one end of contact carrier 32 by a bolt 37 secured within a threaded hole 38 in contact carrier 32.
20 ~ Auxiliary-interlock 29-is--shown having--four differ~
ent contact sets which may alternatively be in different arrangements of normally open (make) and normally cls~sed (break) and make-before-break contacts as desired as des-aribed hereinafter. r~he auxiliary interlock contacts may be interposed in the control circuit of contactor 10 or in the control circuit of a related controller and generally per-form an interlocking function to assure a desired sequence of contactor operation.
Interlock housing 30 is hollow and generally boxlike 30 in shape and comprises similar right and left halves 40 and 41 respectively mated at their open ends and preferably molded 7~ 3 of suitable 1nsulatiny ma-ter.ial such as a thermosetting pheno-lic compound. Ri~ht and left housing halves 40 and 41 may be heId together hy screws ~2 (see Fig. 3). which extend through clearance apertures adjacen-t sidewalls of right housing half 40 and engage threaded metallic inserts (not shown~ molded in left housing half 41. ~nterlock housing 30 may be mounted on bracket 31 by screws (not shown) which are secured within ~ .
threaded inserts 43 molded in housing half 40. .
Four metallic stationary contact posts 44 project :~
from a wall 45 of right housing half 40 into the interior of the housing 30 and also extend exterior of the housing, and four similar metallic stationary contact posts 44 project from a wall 46 of left housing half 41 into the interior of housing 30 and also extend exterior of the housing. Each con~
tact post-44 has a portion 48 of generally triangular cross section disposed within housing 30 which is unitary with two spaced, parallel, flat terminal portions 49 that protrude--through parallel spaced openings 50 molded in wall 45 of hous-ing half 40, or in wall 46 of housing half 41. Stationary con-tact posts 44 may be secured to wall 45 or wall 46 by bending over protruding edges of terminal portions 49 such as shown by ~ ?
reference numeral 52, both interior and exterior of housing 30. The spaced terminal portions 49 of each stationary contact post 44 form a two-prong male connector which may ac-cept a complementary female connector. Barrier walls 53 ~i molded on the exterior of right housing half 40 and on the exterior of left housing half 41 separate adjacent stationary contact post~ 44 to provide high electrical breakdown strength ~:
b.etween auxiliary circuits. The stationary contact posts 44 are preferably fabrlcated of metal such as brass with an o~erlay ' ' , ' ',:
1~476~15 3 of silver upon triangular portion 4g to minimize resistance with the bridging contacts 71 carxied by operating member 32.
Housing halves 40 and 41 have U-shaped apertures 54 in the end walls thereof which face each other to define openings of rectangular cross-section ~when halves 40 and cover 41 are mated~ in which contact carrier 32 slidably reciprocates longitudinally of hbusing 30. In contrast to contact carriers of prior art interlocks which were con-structed of plural insulating pieces held together by bolt means, contact carrier 32 is preferably molded in one piece from suitable insulating material. Contact carrier 32 has an elongated spring-receiving cavity 55 (see Fig. 8, 9 and lO) extending laterally therethrough intermediate its ends and in a plane parallel to its longitudinal axis in which a helical return spring 56 is compressed and held captiye so that the ends of return spring 56 react against the walls of contact carrier 32 defining cavity 55. Elongated ridges 57 (see Fig. 8) are preferably provided on contact carrier 32 along one edge of spring-receiving cavity 55 to prevent removal of spring 56 through one side o~ cavity 55, and-proje~tions--58 ---(see Fig. 9) are preferably provided along the opposite edges of cavity 55 to block lateral movement of the ends of spring 56, thus tending to hold return spring 56 captive within cavity 55.
Elongated abutment-receiving apertures 59 and 60 (see Fig. 8) extend laterally through contact carrier 32 in the plane of its longitudinal axis and which register with the ends of spring-receiving cavit~ 55. An end abutment membex 62a of suitable insulating material such a~ polyester resin bonded glass mat ma~v be interchangeably assembled 3~ within abutment-receiving aperture 59, as shown in FLgs. 7 .
~1347Q83 and 10, so that contact carrier 32 is resiliently normally biased downward and is ope~rated in the upward direction against the force of return spring 56, or end abutment mem-ber 62a may alternatively be assembled within abutment-receiving aperture 60 (in a position not shown) so that contact carrier 32 would be normally biased upward (relative to the position shown in the drawing) and would be operated downward against the force of return spring 56. When end abutment member 62a is assembled within aperture 59, its 10 . ends fit within elongated grooves 63 molded in opposed sidewalls of housing half 40 and which grooves face similar grooves 63 molded in opposed sidewalls of housing half 41, thereby holding end abutment member 62a from movement relative to housing 30. End abutment member 62a has a notch 65 inter-mediate its ends in one sidewall thereof which embraces contact carrier.32 and has a projection 67 in the opposite sidewall thereof intermediate its ends which protrudes into the axial opening in helical return spring 56, thereby normally position-ing contact carrier 32 relative to end abutment member 62a by the force of compressed return spring 56. It will be appreciated that when end abutment member 62a is disposed within abutment-receiving aperture 59, contact carrier 32 is normally biased toward downward movement as shown in Fig. .7 and that reciprocation of contact carrier 32 upward to operate the interlock switch will further compress return spring 56 against end abutment member 62a, which slides within abutmen-t-receiving aperture 5~, to further load re-turn spring 56. End abutment member 62a may be easily disassembled from contact carrier 32 by manually compressing return spring 30 56 and withdrawing end abutment member 62a in a longitudinal ~:`
direction from abutment-receiving aperture 59, and end abut-47~3 ment member 62a may then be turned over and assembled through abutment-receiving aperture 60 at the lowe~ end of return spring 56, in which position its ends fit within elongated grooves 64 molded in opposed sidewalls of housing half 40 and which grooves 64 face similar grooves 6~ molded in the sidewall of housing half 41, thereby preventing movement of end abutment member 62a relative to housing 30. It will be appreciated that when end abutment member 62a is assembled within abutment-receiving aperture 60, contaet carrier 37 is normally biased against downward movement and that reciprocation of contaet carrier 32 downward to operate the interlock will further eompress return spring 56 against end abutment 62a and increase the foree tending to return eontact earrier 32 to its initial position.
Contact carrier 32 may-alternatively be normally~~
held in a central position within housing 30 wherein it is biased against reciprocation in either direction when a centering abutment member 62b having a eentral rectangular cavity 68 which embraces helical return spring 56 is substi-tuted for end abutment member 62a and is assembled to beslidable within both abutment-receivlng apertures 59 and 60 (see Figs. 6, 8 and g). Each end of centering abutment member--62b-has a pair of spaced-projections 69 which fit within grooves 63 and 64 in the sidewalls in housing halves 40 and 41 to prevent movement of centering abutment member 62b relative to housing 30. -Opposite-ends of-return spring 56---react against the ends of rectangular cavity 68 in stationary centering abutment member 62b and also react against the ends of spring-receiving cavity 55 in contact earrier 32, and con-sequently return sprin~ 56 is further eompressed when contaetearrier 32 is reeiprocated in either direction from its normal 7~3 central position so that centering abutment member 62b slides ::
within abutment-receiving aperture 59 o~ ~Q.
Contact carrier 32 carries two bridging metallic contacts 71L (see ~igs. 8 and 11~. which.engage and disengage the stationary contact posts 44 projecting inwardly from wall 45 o~ housing half 40 and also carries two br1dging metal-lic contacts 71U which engage the stationary contact posts 44 extending inwardly from wall 46 of housing half 41. Each bridg- ~:
ing contact 71 is generally of U-shape cross-section in a plane perpendicular to stationary posts 44, and the ends 76 of each ley diverge at an oblique angle to permit engagement with opposed faces of the triangular cross-section portion 48 of a stationary contact post 44. Each leg of bridging contact 71 is bifurcated (see Fig. 12) so that each bridging contact 71 has plural points.of engagement-with the--corresponding sta-tionary contact posts 44, thereby assuring that a particle of dust cannot prevent completion of a low voltage auxiliary circuit controlled thereby, and also substantially increasing `~.
the electrical reliability of the interlock in comparison to ~:
prior art devices which utilized button contacts. Each bridg-ing contact 71 is preferably constructed of beryllium copper ; ~:
and the diverging ends 7~ thereof preferably have an overlay 79 of high-conductivity metal such as silvex and~have -"chisel shape" surfaces 90 to assure high contact pressure per unit area and to facilitate wiping motion with a station-ary contact post 44.
Contact car~iex 32 h.as a pair o~ contact-receiving openings 73U and 74U C~ee Fig. 8~ extending laterall~ there-through wlthin h.ousing half 41 and also has a similar pair of contact receiving openings 73L and 74L extending laterally there-through within hbusing half 40. Contact-receiving opènin~s 73 '' ' - 10 - ~ ~
.,, , :.
:~ . . . . . . .
~,.04L7~83 and 7~ are of rectangular cross-section and permit a bridging contact 71 LSee Fig. 121 to be inserted longitudinally there-through and then turned so that the cross-piece 72 of the U-shaped bridging contact 71 abuts against one end wall of contact-receiving opening 73 or 74. A helical contact spring 75 loaded between the opposite end wall of each contact-receiving opening 73 or 74 and the cross-piece 72 holds the bridging contact 71 captive on contact carrier 32. Each U-shaped bridging contact 71 may be interchangeably assembled on con-tact carrier 32 in a first position wherein its open end facesin one direction (for example, upward as shown by the nor-mally closed "break" contacts in Fig. 6) so that its diverging ends 76 engage and disengage the upper face of the triangular stationary contact portions 48 as contact carrier 32 recipro-cates, or in a second position wherein its open end faces in the opposite direction (~or example, downward as shown by the normally open "make" contacts in Figs. 6 and 7) so that -its diverging ends 76 engage and disengage the lower face of the triangular stationary contact portion 48. The cross-20 ~ piece Z2 of each bridging CG ntact 71 may be positionedagainst either end of the contact-receiving aperture 73 or 74. It will thus be appreciated that bridging contacts 71 may be assembled in any desired arrangement of normally open :
and normally closed contact sets with the stationary contact posts 44. Such arrangement of auxiliary circuit contacts -~
may be easily changed in -the field by merely pushing any bridging contact 71, which it is desired to change, ou-t from its contact-receiving opening 73 or 74 and reversing said bridg-ing contact 71 so that it faces the opposite direction, or so that its cross-piece 72 abuts the opposite end of the contact-rece~ving aperture 73 or 74. ~n contrast, the contact carriers , . . .
~4~ 3 of prior art interlocks and the movable contacts carried there-by were assembled from a multiplicity o~ pieces and required special jigs and fixtures to hold the components in place during construction of the contact carrier assembly, thereb~
permitting fabrication o~ such prior art de~ices only at the factory where the fixtures were'available and virtually pre-venting change of interlock contact arrangement in the field.
Contact-receiving opening 73 is preferably longer than contact-receiving opening 74, (,see Fig. 8) thereby per-mitting make-before-break contacts and also permitting opening and closing of the auxiliary circuits after different lengths -of travel of contact carrier 32. A normally open bridging contact 71 disposed in the longer contact-receiving open-ing 73 can move further within spring-receiving opening 73 after initial engagement with its associated stationary contact posts 44 upon overtravel of contact carrier 32 than is possible for a bridging contact 71 disposed in shorter opening 74, and this structure also permits a bridging contact 71 within longer opening 73 to remain engaged with said posts 44 -under force-of---i*s helical-cont-act-spring -7-5 for a~,longer-time~
than a bridging contact 71 within shorter opening 74 when the operating member 32 reciprocates in the opposite direction. ~' The walls of contact carrier 32 defining the ends ~ ~, of contact-receiving openings 73 and 74 have projec-tions 80 which fit into the axial openings in helical springs 75 and tend to hold springs 75 captive. The height of each bridging ;
contact 71 is greater than that of contact-receiving opening 73 or 74, but the cross-piece 72 of each bridging contact 71 has an indentation 81 ~see Fig. 12~ so that bridging contact 3Q 71 can be'assembled longitudinall~ through'an opening 73 or 74 and then turned so that cross-piece 72 abu-ts one end of the . .
~7~f33 opening and the ed~es 82 of indentation 81 overlap the contact carrier walls and limit late.ral moVement of the bridging contact 71 relative to carrier 32.
~ hile only a single embodiment of the invention has been illustrated and described, it should be understood that we do not intend to be limited to the slngle embodiment for many modificatiGns and variations thereof will be obvious to those skilled in the art.
BACKGROUND OF THE INVENTION
Contactors are often provided with'an auxiliary interlock switch which has a plurality of sets of electrical contacts for controlling auxiliary circuits such as the operating coils of auxiliary devices. ' ;~
Known auxiliary interlock switches are constructed ~ ' 10 from a large numb`er of separate pieces which require special ' fixtures and jigs to hold the pieces together during assem-bly, make change of contact arrangement in the field vir- , tually impossible, and substantially increase both the ~, number of machining and handling operations as well as the cost of the unit.--'Further, the electrical reliability of -known auxiliary interlock switches is relatively low in that ;
contamination of-the contacts~often-prevent completion of a low voltage auxiliary circuit even though the contacts of the interlock are operated into engagement by the electro-20 magnetic contactor. ' OBJECTS OF THE INVENTION
It is an object of the invention to provide an-im-proved auxiliary interlock switch for a contactor which o'bviates the above disadvantages of prior art devices and has substantially fewer parts than known interlocks. It i5 a further object of the invention to provide such an improved auxiliary interlock switch which does not require special ~ , fixtures and jigs to assemble'the parts and wherein the movable contacts are easily assembled on the contact carriex and can be'facilely changed in the'fiel'd to provide any desired arrangement of contact sets. Another'object of the '- 1- ~ -, ~ 7~B3 invention is to provide such an lmproved auxiliary interlock switch which is less expensive than known devices and re~uires ~ewer machining and handl'ing operations to construct.
~ still further object of the invention is to pro-vide such an improved auxiliary interlock switch which can easily be converted so that its reciprocable contact carrier is alternativeIy resiliently biased by the return spring to either a central position or to extreme positions in either direction from the central position. Still another object 10' is to provide such an improved interlock switch for a contactor which, in comparison to prior art auxliary inter-locks, has higher unit contact pressure and substantially improved electrical reliability. ;~' SUMMARY OF THE INVENTION
An auxiliary interlock switch embodying the inven-tion has increased electrical reliability in comparison to known devices ana permits easy-change-of the auxiliary con- '~
tact arrangement in the field. A reciprocable, one-piece insulating contact carrier is provided with a cavity in which a helical return spring is captive and first and second abutment-receiving apertures which register with opposite ends of the spring-receiving cavity and in which an abutment member may interchangeably-ke positioned with its ends affixed to opposed sidewalls of the interloc]~
housing so that the return spring reacts against the abut-ment member and biases the carrier toward reciprocation in a desired direction. The contact carrier also has a plur-- alit~ of contact-receiving apertures in each of which a metallic bridging contact of generally U-shaped croSS section with diYerging ends is held captive by a loaded compression spring with'the'cross-piece of the'U-shaped contact abutting 1C)47~83 against one end o~ the contact-receiVing aperture. The ~ridging contacts may be easily removed in the field from the contact-receiving ape.rtures and reversed in direction to provide normall~ open or normally closed sets of auxiliary contacts with the stationary contact posts, or may alterna-tively be disposed against the opposite end of the contact-receiving aperture in order to provide different arrangements of normally open and normally closed auxiliary contact sets, as desired. The bridging contacts are of resilient material and the legs thereof are bïfurcated and have "chisel" shape surfaces which provide plural points of high unit area pressure arrangement with unitary stationary contact posts affixed to the interlock housing and substantially increase electrical reliability. -DESCRIPTION OF THE DRAWINGS
These and other objects and advantages of the in-vention will be more readily apparent from the following detailed description when considered in conjunction with the accompanying drawing wherein:
Fig. l.. is a fron.t view.. o~.a.. known contactor pro--~-vided with.the improved auxiliary interlock switch of the .
invention;
Figs. 2, 3 and 4 are left side, front and bottom views respectively of the housing of the auxiliary interlock switch embod.ying the invention shown in Fig. l;
Fig. 5 is a view of the open end of the right half of the interlock switch housing shown in Figs. 2-4 with the left housing half, contact carrier, and abutment member removed;
Fig. 6 is a View simil~r to Fig~ 5 but having the right housing half assembled with the contact carrier and a centering abutment member which biases the contact to a central position within the hbusing;
IL7~il3 Fig. 7 is a view similar to F~. 6 havin~ the con-tact carrier assembled with an end abutment member which biases the contact carrier to an extreme position in one direction;
Fig. 8 is a right side view of the reciprocable con-tact carrier removed from the housing and assembled with a ;
centering abutment member;
Fig. 9 is a sectional view taken along line IX-IX ~:
of Fig. 8;
10 ' Fig. 10 is a section view through the reciprocable contact carrier removed from the housing and assembled with an end abutment member;
Fig. 11 is a partial vertical, section view taken through the auxiliary interlock switch along line XI-XI of Fig. 6; and Fig. 12 is a perspective view of one of the bridging ';~
contacts.
DETAILED DESCRIPTION
Referring to Fig. 1 of the drawing, a known con- ', -tactor--10-may have-a U-shaped=ferromagnetic frame-~l-l which-~embraces a---cylindrical operating coil 12 wound in surrounding relation to a ferromagnetic core 14 extending axially of coil 12. A ferromagnetic armature 16 pivotally connected to one leg 17 of frame 11 is pulled against the other leg 18 of the frame to operate the contactor when coil 12 is ener- ,~
gized. The contactor movable main contact 19 is carried by armature 16 and may be electrically connected by a flexible lead ~ot shownl to a texminal block 2Q and .is adapted to engage a main stationary contact 22 when; armature 16 is attracted to core'l4. Stationary contact 22 is electrically connected to one'end of a metallic bus bar 23'which at its , ~Ofl~7~3 opposi-te end is connected to a helical elec-trical blowout coil 24. The arc, which is formed when contacts l9 and 22 separate, transfers to and is interrupted in an arc chute 26 having pole pieces 27 ~only one of which is shown~ between which the magnetic field generated by blowout coil 24 ex-tends. Only one of the flux carrying members 28 is shown which transfer the magnetic flux from blowout coil 24 to pole pieces 27.
The auxlliary interlock switch 29 for controlling auxiliary circuits includes an insulating housing 30 mounted on 10 a support bracket 31 and is actuated by reciprocation of an elongated operating member, or contact carrier 32 slidably mounted within housing 30. The ends of a U-shaped interlock actua*ing member 33 are secured to armature 16, and the cross-piece 34 of member 33 actuates contact carrier 32 longitudinally to operate the interlock switch 29 when armature 16 is attracted to frame ll. Cross-piece 34 may fit within an elongated groove 35 provided in a member 36 attached to one end of contact carrier 32 by a bolt 37 secured within a threaded hole 38 in contact carrier 32.
20 ~ Auxiliary-interlock 29-is--shown having--four differ~
ent contact sets which may alternatively be in different arrangements of normally open (make) and normally cls~sed (break) and make-before-break contacts as desired as des-aribed hereinafter. r~he auxiliary interlock contacts may be interposed in the control circuit of contactor 10 or in the control circuit of a related controller and generally per-form an interlocking function to assure a desired sequence of contactor operation.
Interlock housing 30 is hollow and generally boxlike 30 in shape and comprises similar right and left halves 40 and 41 respectively mated at their open ends and preferably molded 7~ 3 of suitable 1nsulatiny ma-ter.ial such as a thermosetting pheno-lic compound. Ri~ht and left housing halves 40 and 41 may be heId together hy screws ~2 (see Fig. 3). which extend through clearance apertures adjacen-t sidewalls of right housing half 40 and engage threaded metallic inserts (not shown~ molded in left housing half 41. ~nterlock housing 30 may be mounted on bracket 31 by screws (not shown) which are secured within ~ .
threaded inserts 43 molded in housing half 40. .
Four metallic stationary contact posts 44 project :~
from a wall 45 of right housing half 40 into the interior of the housing 30 and also extend exterior of the housing, and four similar metallic stationary contact posts 44 project from a wall 46 of left housing half 41 into the interior of housing 30 and also extend exterior of the housing. Each con~
tact post-44 has a portion 48 of generally triangular cross section disposed within housing 30 which is unitary with two spaced, parallel, flat terminal portions 49 that protrude--through parallel spaced openings 50 molded in wall 45 of hous-ing half 40, or in wall 46 of housing half 41. Stationary con-tact posts 44 may be secured to wall 45 or wall 46 by bending over protruding edges of terminal portions 49 such as shown by ~ ?
reference numeral 52, both interior and exterior of housing 30. The spaced terminal portions 49 of each stationary contact post 44 form a two-prong male connector which may ac-cept a complementary female connector. Barrier walls 53 ~i molded on the exterior of right housing half 40 and on the exterior of left housing half 41 separate adjacent stationary contact post~ 44 to provide high electrical breakdown strength ~:
b.etween auxiliary circuits. The stationary contact posts 44 are preferably fabrlcated of metal such as brass with an o~erlay ' ' , ' ',:
1~476~15 3 of silver upon triangular portion 4g to minimize resistance with the bridging contacts 71 carxied by operating member 32.
Housing halves 40 and 41 have U-shaped apertures 54 in the end walls thereof which face each other to define openings of rectangular cross-section ~when halves 40 and cover 41 are mated~ in which contact carrier 32 slidably reciprocates longitudinally of hbusing 30. In contrast to contact carriers of prior art interlocks which were con-structed of plural insulating pieces held together by bolt means, contact carrier 32 is preferably molded in one piece from suitable insulating material. Contact carrier 32 has an elongated spring-receiving cavity 55 (see Fig. 8, 9 and lO) extending laterally therethrough intermediate its ends and in a plane parallel to its longitudinal axis in which a helical return spring 56 is compressed and held captiye so that the ends of return spring 56 react against the walls of contact carrier 32 defining cavity 55. Elongated ridges 57 (see Fig. 8) are preferably provided on contact carrier 32 along one edge of spring-receiving cavity 55 to prevent removal of spring 56 through one side o~ cavity 55, and-proje~tions--58 ---(see Fig. 9) are preferably provided along the opposite edges of cavity 55 to block lateral movement of the ends of spring 56, thus tending to hold return spring 56 captive within cavity 55.
Elongated abutment-receiving apertures 59 and 60 (see Fig. 8) extend laterally through contact carrier 32 in the plane of its longitudinal axis and which register with the ends of spring-receiving cavit~ 55. An end abutment membex 62a of suitable insulating material such a~ polyester resin bonded glass mat ma~v be interchangeably assembled 3~ within abutment-receiving aperture 59, as shown in FLgs. 7 .
~1347Q83 and 10, so that contact carrier 32 is resiliently normally biased downward and is ope~rated in the upward direction against the force of return spring 56, or end abutment mem-ber 62a may alternatively be assembled within abutment-receiving aperture 60 (in a position not shown) so that contact carrier 32 would be normally biased upward (relative to the position shown in the drawing) and would be operated downward against the force of return spring 56. When end abutment member 62a is assembled within aperture 59, its 10 . ends fit within elongated grooves 63 molded in opposed sidewalls of housing half 40 and which grooves face similar grooves 63 molded in opposed sidewalls of housing half 41, thereby holding end abutment member 62a from movement relative to housing 30. End abutment member 62a has a notch 65 inter-mediate its ends in one sidewall thereof which embraces contact carrier.32 and has a projection 67 in the opposite sidewall thereof intermediate its ends which protrudes into the axial opening in helical return spring 56, thereby normally position-ing contact carrier 32 relative to end abutment member 62a by the force of compressed return spring 56. It will be appreciated that when end abutment member 62a is disposed within abutment-receiving aperture 59, contact carrier 32 is normally biased toward downward movement as shown in Fig. .7 and that reciprocation of contact carrier 32 upward to operate the interlock switch will further compress return spring 56 against end abutment member 62a, which slides within abutmen-t-receiving aperture 5~, to further load re-turn spring 56. End abutment member 62a may be easily disassembled from contact carrier 32 by manually compressing return spring 30 56 and withdrawing end abutment member 62a in a longitudinal ~:`
direction from abutment-receiving aperture 59, and end abut-47~3 ment member 62a may then be turned over and assembled through abutment-receiving aperture 60 at the lowe~ end of return spring 56, in which position its ends fit within elongated grooves 64 molded in opposed sidewalls of housing half 40 and which grooves 64 face similar grooves 6~ molded in the sidewall of housing half 41, thereby preventing movement of end abutment member 62a relative to housing 30. It will be appreciated that when end abutment member 62a is assembled within abutment-receiving aperture 60, contaet carrier 37 is normally biased against downward movement and that reciprocation of contaet carrier 32 downward to operate the interlock will further eompress return spring 56 against end abutment 62a and increase the foree tending to return eontact earrier 32 to its initial position.
Contact carrier 32 may-alternatively be normally~~
held in a central position within housing 30 wherein it is biased against reciprocation in either direction when a centering abutment member 62b having a eentral rectangular cavity 68 which embraces helical return spring 56 is substi-tuted for end abutment member 62a and is assembled to beslidable within both abutment-receivlng apertures 59 and 60 (see Figs. 6, 8 and g). Each end of centering abutment member--62b-has a pair of spaced-projections 69 which fit within grooves 63 and 64 in the sidewalls in housing halves 40 and 41 to prevent movement of centering abutment member 62b relative to housing 30. -Opposite-ends of-return spring 56---react against the ends of rectangular cavity 68 in stationary centering abutment member 62b and also react against the ends of spring-receiving cavity 55 in contact earrier 32, and con-sequently return sprin~ 56 is further eompressed when contaetearrier 32 is reeiprocated in either direction from its normal 7~3 central position so that centering abutment member 62b slides ::
within abutment-receiving aperture 59 o~ ~Q.
Contact carrier 32 carries two bridging metallic contacts 71L (see ~igs. 8 and 11~. which.engage and disengage the stationary contact posts 44 projecting inwardly from wall 45 o~ housing half 40 and also carries two br1dging metal-lic contacts 71U which engage the stationary contact posts 44 extending inwardly from wall 46 of housing half 41. Each bridg- ~:
ing contact 71 is generally of U-shape cross-section in a plane perpendicular to stationary posts 44, and the ends 76 of each ley diverge at an oblique angle to permit engagement with opposed faces of the triangular cross-section portion 48 of a stationary contact post 44. Each leg of bridging contact 71 is bifurcated (see Fig. 12) so that each bridging contact 71 has plural points.of engagement-with the--corresponding sta-tionary contact posts 44, thereby assuring that a particle of dust cannot prevent completion of a low voltage auxiliary circuit controlled thereby, and also substantially increasing `~.
the electrical reliability of the interlock in comparison to ~:
prior art devices which utilized button contacts. Each bridg-ing contact 71 is preferably constructed of beryllium copper ; ~:
and the diverging ends 7~ thereof preferably have an overlay 79 of high-conductivity metal such as silvex and~have -"chisel shape" surfaces 90 to assure high contact pressure per unit area and to facilitate wiping motion with a station-ary contact post 44.
Contact car~iex 32 h.as a pair o~ contact-receiving openings 73U and 74U C~ee Fig. 8~ extending laterall~ there-through wlthin h.ousing half 41 and also has a similar pair of contact receiving openings 73L and 74L extending laterally there-through within hbusing half 40. Contact-receiving opènin~s 73 '' ' - 10 - ~ ~
.,, , :.
:~ . . . . . . .
~,.04L7~83 and 7~ are of rectangular cross-section and permit a bridging contact 71 LSee Fig. 121 to be inserted longitudinally there-through and then turned so that the cross-piece 72 of the U-shaped bridging contact 71 abuts against one end wall of contact-receiving opening 73 or 74. A helical contact spring 75 loaded between the opposite end wall of each contact-receiving opening 73 or 74 and the cross-piece 72 holds the bridging contact 71 captive on contact carrier 32. Each U-shaped bridging contact 71 may be interchangeably assembled on con-tact carrier 32 in a first position wherein its open end facesin one direction (for example, upward as shown by the nor-mally closed "break" contacts in Fig. 6) so that its diverging ends 76 engage and disengage the upper face of the triangular stationary contact portions 48 as contact carrier 32 recipro-cates, or in a second position wherein its open end faces in the opposite direction (~or example, downward as shown by the normally open "make" contacts in Figs. 6 and 7) so that -its diverging ends 76 engage and disengage the lower face of the triangular stationary contact portion 48. The cross-20 ~ piece Z2 of each bridging CG ntact 71 may be positionedagainst either end of the contact-receiving aperture 73 or 74. It will thus be appreciated that bridging contacts 71 may be assembled in any desired arrangement of normally open :
and normally closed contact sets with the stationary contact posts 44. Such arrangement of auxiliary circuit contacts -~
may be easily changed in -the field by merely pushing any bridging contact 71, which it is desired to change, ou-t from its contact-receiving opening 73 or 74 and reversing said bridg-ing contact 71 so that it faces the opposite direction, or so that its cross-piece 72 abuts the opposite end of the contact-rece~ving aperture 73 or 74. ~n contrast, the contact carriers , . . .
~4~ 3 of prior art interlocks and the movable contacts carried there-by were assembled from a multiplicity o~ pieces and required special jigs and fixtures to hold the components in place during construction of the contact carrier assembly, thereb~
permitting fabrication o~ such prior art de~ices only at the factory where the fixtures were'available and virtually pre-venting change of interlock contact arrangement in the field.
Contact-receiving opening 73 is preferably longer than contact-receiving opening 74, (,see Fig. 8) thereby per-mitting make-before-break contacts and also permitting opening and closing of the auxiliary circuits after different lengths -of travel of contact carrier 32. A normally open bridging contact 71 disposed in the longer contact-receiving open-ing 73 can move further within spring-receiving opening 73 after initial engagement with its associated stationary contact posts 44 upon overtravel of contact carrier 32 than is possible for a bridging contact 71 disposed in shorter opening 74, and this structure also permits a bridging contact 71 within longer opening 73 to remain engaged with said posts 44 -under force-of---i*s helical-cont-act-spring -7-5 for a~,longer-time~
than a bridging contact 71 within shorter opening 74 when the operating member 32 reciprocates in the opposite direction. ~' The walls of contact carrier 32 defining the ends ~ ~, of contact-receiving openings 73 and 74 have projec-tions 80 which fit into the axial openings in helical springs 75 and tend to hold springs 75 captive. The height of each bridging ;
contact 71 is greater than that of contact-receiving opening 73 or 74, but the cross-piece 72 of each bridging contact 71 has an indentation 81 ~see Fig. 12~ so that bridging contact 3Q 71 can be'assembled longitudinall~ through'an opening 73 or 74 and then turned so that cross-piece 72 abu-ts one end of the . .
~7~f33 opening and the ed~es 82 of indentation 81 overlap the contact carrier walls and limit late.ral moVement of the bridging contact 71 relative to carrier 32.
~ hile only a single embodiment of the invention has been illustrated and described, it should be understood that we do not intend to be limited to the slngle embodiment for many modificatiGns and variations thereof will be obvious to those skilled in the art.
Claims (17)
1. An electrical circuit making and breaking interlock switch comprising, in combination, a hollow insulating housing having at least two pair of stationary contact posts projecting inwardly from a wall thereof, an insulating contact carrier mounted for reciprocation through said housing and being accessible from the housing exterior, said contact carrier having a spring-receiving cavity therein and elongated first and second abutment-receiving apertures extending therethrough which register with opposite ends of said spring-receiving cavity, an abutment member adapted to be releasably assembled to said contact carrier and extend freely through one of said abutment-receiving apertures so that said contact carrier is movable relative thereto and having its ends in engagement with opposed walls of said housing to prevent movement thereof as said contact carrier reciprocates, a helical return spring compressed within said spring-receiving cavity and reacting at one end against said abutment member assembled within said one abutment-receiving aperture to normally resiliently bias said contact carrier against reciprocation in one direction, and a pair of unitary metallic bridging contacts carried by said contact carrier each of which is adapted to engage and bridge between the stationary contact posts of one of said pairs as said contact carrier reciprocates in one direction and to disengage them as said contact carrier reciprocates in the opposite direction.
2. An interlock switch in accordance with claim 1 wherein said abutment member extends into and slides within both said abutment-receiving apertures and also has a spring-receiving opening therein which embraces and holds captive said helical return spring so that both ends of said return spring react against said abutment member and resiliently bias said contact carrier against movement in either direction from a central position within said housing.
3. An interlock switch in accordance with claim 1 wherein said contact carrier also has a pair of elongated contact-receiving openings extending laterally therethrough and each said bridging contact protrudes through one of said contact-receiving openings and is held captive against one end of said opening by a compression spring loaded between it and the other end of said contact-receiving opening, said bridging contact being adapted to be interchangeably held captive within said contact-receiving opening by said compression spring in a first position wherein it engages one side of a pair of said stationary contact posts or to be reversed and held captive by said compression spring within said opening in a second position wherein it is adapted to engage the opposite side of said pair of stationary contact posts.
4. An interlock switch in accordance with claim 3 wherein said pair of contact-receiving openings are spaced apart longitudinally of said contact carrier and each of said bridging contacts is generally of U-shape cross section in a plane perpendicular to said stationary contact posts with the legs thereof diverging at an oblique angle, said U-shaped bridging contacts being adapted to be alternatively assembled within said contact-receiving openings in said first and second positions wherein the open ends thereof face in opposite directions and engages opposite sides of a pair of said stationary contact posts.
5. An interlock switch in accordance with claim 4 wherein each leg of said W-shape bridging contacts is bifurcated to provide plural points of engagement with a stationary contact post.
6. An interlock switch in accordance with claim 5 wherein said bridging contacts are of resilient metal and the bifuracted ends of said diverging legs have chisel-shape surfaces which provide high contact pressure per unit area with said stationary contact posts.
7. An interlock switch in accordance with claim 6 wherein each of said stationary contact posts is one-piece and protrudes through said wall of said housing, the portion of each said stationary contact post interior of said housing being of generally V-shaped cross-section so that said diverging ends of said bridging contact may engage either side of said stationary contact post with a wiping action.
8. An interlock switch in accordance with claim 7 wherein each of said U-shaped bridging contacts is adapted to be interchangeably held by a compression spring within said contact-receiving opening with the cross-piece thereof abutting against said one end of said opening or against the opposite end of said opening.
9. An interlock switch in accordance with claim 3 wherein said housing has a plurality of pairs of first said stationary contact posts extending inwardly of said housing from a first wall thereof and a plurality of pairs of second said stationary contact posts extending inwardly of said housing from a second wall thereof opposite said first wall, and said contact carrier has a plurality of first said contact-receiving openings which receive said bridging contacts that engage said first stationary contact posts and a plurality of second contact-receiving openings which receive said bridging contacts that engage said second stationary contact posts.
10. An interlock switch in accordance with claim 9 wherein said return spring-receiving opening and said abutment receiving opening in said contact carrier are disposed in a common plane perpendicular to and disposed between said first and said second stationary contact posts and also disposed between said first and second contact-receiving openings in said contact carrier.
11. An interlock switch in accordance with claim 10 wherein said housing comprises two generally box-shaped halves with open sides facing each other, and at least one of said halves has grooves in the interior surface of opposing side walls thereof which receive the ends of said abutment member.
12. An interlock switch in accordance with claim 6 wherein one of said contact-receiving openings in said contact carrier is longer than the other so that one of said bridging contacts can engage or disengage its associated stationary contact posts before the other bridging contact engages or disengages its associated stationary contact posts.
13. An interlock switch in accordance with claim 1 wherein said contact carrier has a pair of contact-receiving openings extending laterally therethrough spaced apart longitudinally of said contact carrier, and each said bridging contact protrudes through one of said contact-receiving opening and is held captive against one end of said contact-receiving opening by a compression spring loaded between it and the other end of said contact-receiving opening, said bridging contact being adapted to be interchangeably held by said compression spring in a first position within said contact-receiving opening wherein it is adapted to engage one side of a pair of said stationary contact posts or to be reversed and held in said opening by said compression spring in a second position wherein it is adapted to engage the opposite side of said stationary contact posts.
14. An interlock switch in accordance with claim 13 wherein each of said bridging contacts is of generally U-shape cross-section in a plane perpendicular to said stationary contact posts and the legs thereof diverge at an oblique angle and are adapted to engage said stationary contacts posts, said legs of said U-shaped bridging members being bifurcated to provide plural points of engagement with said stationary contact posts.
15. An interlock switch in accordance with claim 14 wherein each of said stationary contact posts is one-piece and protrudes through said wall of said housing, the portion of said stationary contact posts interior of said housing being of generally V-shaped cross-section in a plane transverse to said posts so that said diverging ends of said bridging contact may engage either side of said stationary contact posts with a wiping action.
16. An interlock switch in accordance with claim 15 wherein said bridging contacts are of resilient metal and the ends of said bifurcated legs generally have chisel-shape engagement surfaces which provide high contact pressure per unit area with said stationary contact posts.
17. An interlock switch in accordance with claim 16 wherein each of said bridging contacts is adapted to be interchangeably held by said compression spring within said contact-receiving opening so that the cross-piece of said U-shaped bridging contacts abuts against either one end of said opening or against the opposite end of said opening.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/615,688 US4006322A (en) | 1975-09-22 | 1975-09-22 | Auxiliary interlock switch with interchangeable and reversible chisel-shaped contacts and spring biasing mechanism |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1047083A true CA1047083A (en) | 1979-01-23 |
Family
ID=24466434
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA251,796A Expired CA1047083A (en) | 1975-09-22 | 1976-05-04 | Auxiliary interlock switch with interchangeable and reversible chisel-shaped contacts and spring biasing mechanism |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US4006322A (en) |
| CA (1) | CA1047083A (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4064381A (en) * | 1976-02-18 | 1977-12-20 | Westinghouse Electric Corporation | Pushbutton switch assembly having floating type bridging contact and lost motion actuator |
| US4112273A (en) * | 1977-10-28 | 1978-09-05 | General Motors Corporation | Push-pull electric switch |
| FR2452775B1 (en) * | 1979-03-29 | 1985-06-21 | Manuf Alpes Fses | IMPROVEMENTS ON QUICK-OPERATING ELECTRIC SWITCHES |
| DE3136354C2 (en) * | 1981-09-14 | 1985-10-17 | Siemens AG, 1000 Berlin und 8000 München | Contact arrangement for electrical switching devices |
| DE3140199C2 (en) * | 1981-10-09 | 1984-03-22 | Rudolf Schadow Gmbh, 1000 Berlin | Push-button switches, in particular push-button switches with low key presses for input keyboards |
| US4504713A (en) * | 1983-07-13 | 1985-03-12 | Adams Elevator Equipment Company | Push button electrical switch assembly |
| AUPO815997A0 (en) * | 1997-07-23 | 1997-08-14 | Gerard Industries Pty Ltd | Improved electrical switch |
| US7400477B2 (en) * | 1998-08-24 | 2008-07-15 | Leviton Manufacturing Co., Inc. | Method of distribution of a circuit interrupting device with reset lockout and reverse wiring protection |
| US6180899B1 (en) * | 1999-01-04 | 2001-01-30 | Siemens Energy & Automation, Inc. | Semi-bifurcated electrical contacts |
| US6822173B1 (en) * | 2000-06-07 | 2004-11-23 | Moeller Gmbh | Contact element |
| WO2008006147A1 (en) * | 2006-07-10 | 2008-01-17 | Relay Monitoring Systems Pty. Limited | Improved relay |
| US7498538B1 (en) * | 2007-07-20 | 2009-03-03 | Judco Manufacturing, Inc. | Sliding contact switch |
| CN102067402A (en) * | 2008-07-07 | 2011-05-18 | 立维腾制造有限公司 | Fault circuit interrupter device |
| US20100224467A1 (en) * | 2009-03-03 | 2010-09-09 | General Electric Company | Field interchangeable auxilliary switch |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2756291A (en) * | 1953-03-05 | 1956-07-24 | Allis Chalmers Mfg Co | Switch with reversible contacts and reversible contact carrier |
| US2924685A (en) * | 1957-09-26 | 1960-02-09 | Gen Electric | Magnetic switch |
| US3253092A (en) * | 1963-11-04 | 1966-05-24 | Clark Controller Co | Double pole switch with reversible contact structure |
| FR1435781A (en) * | 1964-06-22 | 1966-04-22 | Telemecanique Electrique | Improvements to the contact poles of current breaking devices |
| US3272949A (en) * | 1964-08-14 | 1966-09-13 | Allen Bradley Co | Bifurcated parallel contacts for relay |
| US3320392A (en) * | 1965-10-15 | 1967-05-16 | Westinghouse Electric Corp | Electric control device with improved contact structure |
| US3544929A (en) * | 1969-01-17 | 1970-12-01 | Ite Imperial Corp | Industrial control relay |
-
1975
- 1975-09-22 US US05/615,688 patent/US4006322A/en not_active Expired - Lifetime
-
1976
- 1976-05-04 CA CA251,796A patent/CA1047083A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US4006322A (en) | 1977-02-01 |
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